Endovascular therapy for pathology of the descending thoracic aorta: current status and indications

Interventional management of aortic dissection and other pathologies of the descending aorta by use of stent-grafts evolved slowly in anticipation of the risk of paraplegia from spinal artery occlusion, a complication known to occur in up to 18% after surgery. With ongoing technical improvement a large series of type B dissection cases has now been successfully treated by endovascular stent-graft placement using the concept of sealing the most proximal entry tears to the dissecting process without neurological sequelae. Recent studies have demonstrated that closure of the entry tear is essential to depressurise the false lumen, reconstruct the aortic wall and reduce total aortic diameter. Entry tear closure promotes both thrombus formation in the false lumen and remodeling of the entire aorta. Various observational studies and registries have shown that the use of a customised stent-graft is an effective method to exclude an enlarging and aneurysmal dilated false lumen by sealing of the proximal entry tear. The absence of a distal reentry tear is desirable but not a prerequisite. Besides dissection, however, focal true (or false) aneurysm of the descending thoracic aorta represents another interesting target for endovascular repair instead of open surgical repair. Similarly, penetrating aortic ulcers, often originating from a localised intramural haematoma of the aorta, is evolving as a new attractive indication for stent-grafting, both in emergency and elective scenarios. Moreover, partial or complete rupture occuring as a result of deceleration trauma appears to be amenable to either emergent or delayed endovascular management. Stabilisation of the disrupted aorta with stent-graft has proven beneficial, with reconstruction of the inner lining by virtue of the endoprothesis to prevent enlargement, aneurysm formation and eventual rupture.